Hi!

Ludovic Courtès <ludo@gnu.org> skribis:

> Jesse (and anyone else experiencing this!), could you try to (1)
> reconfigure with this patch, (2) reboot, (3) try to halt the system to
> reproduce the crash, and (4) retrieve a backtrace from the ‘core’ file?
>
> For #4, you’ll have to do something along these lines once you’ve
> rebooted after the crash:
>
>   sudo gdb /run/current-system/profile/bin/guile /core
>
> and then type “thread apply all bt” at the GDB prompt.

It turns out the previous patch didn’t work; in short, we really have to
use async-signal-safe functions only from the signal handler, so this
has to be done in C.

The attached patch does that.  I’ve tried it with ‘guix system
container’ and it seems to dump core as expected, from what I can see.

Let me know if you manage to reproduce the bug and to get a core dumped
with this patch.

To everyone reading this: if you’re experiencing shepherd crashes,
please raise your hand :-) and consider applying this patch so we can
gather debugging info!

Thanks,
Ludo’.